docs: def redis_from_url(url):
      """
      Converts a redis URL used by celery into a `redis.Redis` object.
      """
      # Makes sure that we only try to import redis when we need
      # to use it
      import redis
  
      url = url or ""
      parsed_url = urlparse(url)
      if parsed_url.scheme != "redis":
          return None
  
      kwargs = {}
      match = PASS_HOST_PORT.match(parsed_url.netloc)
      if match.group('password') is not None:
          kwargs['password'] = match.group('password')
      if match.group('host') is not None:
          kwargs['host'] = match.group('host')
      if match.group('port') is not None:
          kwargs['port'] = int(match.group('port'))
  
      if len(parsed_url.path) > 1:
          # Removes "/" from the beginning
          kwargs['db'] = int(parsed_url.path[1:])
  
      return redis.StrictRedis(**kwargs)